Field of the Invention
The present invention relates to a conductive sheet and a touch panel.
Description of the Related Art
In recent years, touch panels are frequently used as input devices for portable terminals and computers. Such a touch panel is placed on a surface of a display, and performs an input operation by detecting a position touched with a finger or the like. For example, a resistance film type and a capacitive type are known as a position detecting method for a touch panel.
For example, in a capacitive touch panel, indium tin oxide (ITO) is used as a material of a transparent electrode pattern, from the perspective of visibility. ITO, however, has a high wiring resistance and does not have a sufficient transparency, and hence it is discussed that a transparent electrode pattern formed using metal thin wires is used for a touch panel.
Studies on transparent conductive films formed using metal thin wires are continued as disclosed in, for example, U.S. Patent Application Publication No. 2004/0229028 and Pamphlet of International Publication No. WO 2006/001461. If an electrode is formed by arranging a large number of grids made of metallic thin wires (metal thin wires), the surface resistance is considered to be reduced. For example, Japanese Patent Application Laid-Open No. 5-224818, Pamphlet of International Publication No. WO 1995/27334, U.S. Patent Application Publication No. 2004/0239650, U.S. Pat. No. 7,202,859, Pamphlet of International Publication No. WO 1997/18508 and Japanese Patent Application Laid-Open No. 2003-099185 are known as touch panels in which metal thin wires are used to form electrodes.
Japanese Patent Application Laid-Open No. 2010-277392 discloses a touch panel including: a plurality of first detection electrodes that are made of net-like conductive wires and are placed in parallel in one direction; and a plurality of second detection electrodes that are made of net-like conductive wires and are placed in parallel in a direction orthogonal to that of the first detection electrodes.